<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      //http://developer.duyiedu.com/edu/testJsonp
      var $ = {
        ajax: function (obj) {
          var url = obj.url;
          var type = obj.type;
          var dataType = obj.dataType;
          var targetProtocol = '';
          var targetHost = '';

          if (url.indexOf('http://') == 0 || url.indexOf('https://') == 0) {
            var targetURL = new URL(url);
            targetProtocol = targetURL.protocol;
            targetHost = targetURL.host;
          } else {
            targetProtocol = location.protocol;
            targetHost = location.host;
          }

          if ((dataType = 'jsonp')) {
            if (
              location.protocol == targetProtocol &&
              location.host == targetHost
            ) {
            } else {
              var script = document.createElement('script');
              var cb = 'JQ' + Math.floor(Math.random() * 10000000);
              window.cb = function (data) {
                console.log(data);
              };
              script.src = url + '?callback=' + cb;
              script.id = cb;
              document.body.appendChild(script);
            }
          }
        },
      };
      $.ajax({
        url: 'http://developer.duyiedu.com/edu/testJsonp',
        type: 'GET',
        dataType: 'jsonp',
        success: function (data) {
          console.log(data);
        },
      });
    </script>
  </body>
</html>
